1. Field of the Invention
The present invention relates to a grader blade used on a motor or tractor driven grader for grading road beds, ground surfaces and the like. More particularly, the present invention relates to grader blades having carbide inserts or other wear resistant welded surfaces along the ground engaging edge for better wear resistance.
2. Description of the Related Art
Ground engaging tools have been developed to maintain or create a desired ground surface, particularly for roadways. Conventional ground engaging machines generally employ a moldboard that has a scoop-like or concave shape, such as utilized on a grader, scraper or snow plow. The moldboard is pushed or pulled across the ground in order to scrape, grade, or otherwise level the ground surface. In order to reduce wear and tear on the moldboard, an extension piece, called a grader blade, is commonly mounted on the moldboard and used for the ground shaping.
Grader blades are commonly made of materials having a much higher degree of wear-resistance than the moldboard, which is typically made of steel. The grader blades are then secured longitudinally along to the lower portion of the moldboard by screws or bolts. Once the grader blade becomes worn, it can be easily removed and replaced with a new grader blade.
Grader blades have been developed having inserts along the front leading edge of the blade. The inserts are typically made of a highly wear-resistant material in order to reduce wear on the entire blade. One such grader blade is shown in U.S. Pat. No. 4,770,253, issued to Hallisy, et al. entitled "Grader Blade with Tiered Inserts on Leading Edge."
As shown in the aforesaid Hallisy patent, the inserts provided for grader blades typically run the entire front length of the blade. However, U.S. Pat. No. 1,922,917, issued to Russell, et al. entitled "Grader Blade", shows a grader blade having a plurality of teeth located at spaced intervals along the lower edge of the grader blade. The teeth protrude from the grader blade in order to cut knolls, mounds or ridges in the ground surface. In addition, U.S. Pat. No. 4,011,051, issued to Helton, et al., entitled "Composite Wear-Resistant Alloy, and Tools from Same" shows a wear-resistant insert secured to the back face of the grader blade.
Another grader blade having an insert is shown in U.S. Pat. No. 4,086,966 to Lanz, et al., entitled "Composite Ground Engaging Tool." Lanz, et al. provide a grader blade with a high wear-resistant insert located centrally within the lower portion of the blade so that the insert is sandwiched between the front and rear surfaces of the blade.
Conventional grader blades secure the insert to the grader blade by brazing or welding. These techniques have sometimes been found undesirable because the inserts may become loose and fall off during high-impact grading, thus resulting in premature blade failure.